/**
	 * Given an unsuccessful analysis, delegate to the block comment command
	 */
	private _executeBlockComment(model: editorCommon.ITokenizedModel, builder: editorCommon.IEditOperationBuilder, s: Selection): void {
		model.tokenizeIfCheap(s.startLineNumber);
		let languageId = model.getLanguageIdAtPosition(s.startLineNumber, s.startColumn);
		let config = LanguageConfigurationRegistry.getComments(languageId);
		if (!config || !config.blockCommentStartToken || !config.blockCommentEndToken) {
			// Mode does not support block comments
			return;
		}

		var startToken = config.blockCommentStartToken;
		var endToken = config.blockCommentEndToken;

		var ops = this._attemptRemoveBlockComment(model, s, startToken, endToken);
		if (!ops) {
			if (s.isEmpty()) {
				var lineContent = model.getLineContent(s.startLineNumber);
				var firstNonWhitespaceIndex = strings.firstNonWhitespaceIndex(lineContent);
				if (firstNonWhitespaceIndex === -1) {
					// Line is empty or contains only whitespace
					firstNonWhitespaceIndex = lineContent.length;
				}
				ops = BlockCommentCommand._createAddBlockCommentOperations(
					new Range(s.startLineNumber, firstNonWhitespaceIndex + 1, s.startLineNumber, lineContent.length + 1), startToken, endToken
				);
			} else {
				ops = BlockCommentCommand._createAddBlockCommentOperations(
					new Range(s.startLineNumber, model.getLineFirstNonWhitespaceColumn(s.startLineNumber), s.endLineNumber, model.getLineMaxColumn(s.endLineNumber)), startToken, endToken
				);
			}

			if (ops.length === 1) {
				// Leave cursor after token and Space
				this._deltaColumn = startToken.length + 1;
			}
		}
		this._selectionId = builder.trackSelection(s);
		for (var i = 0; i < ops.length; i++) {
			builder.addEditOperation(ops[i].range, ops[i].text);
		}
	}

	/**
	 * Do an initial pass over the lines and gather info about the line comment string.
	 * Returns null if any of the lines doesn't support a line comment string.
	 */
	public static _gatherPreflightCommentStrings(model:editorCommon.ITokenizedModel, startLineNumber: number, endLineNumber: number): ILinePreflightData[] {
		var lines: ILinePreflightData[] = [],
			config:ICommentsConfiguration,
			commentStr:string,
			seenModes: {[modeId:string]:string;} = Object.create(null),
			i:number,
			lineCount:number,
			lineNumber:number,
			mode: IMode,
			modeId: string;

		for (i = 0, lineCount = endLineNumber - startLineNumber + 1; i < lineCount; i++) {
			lineNumber = startLineNumber + i;
			mode = model.getModeAtPosition(lineNumber, 1);
			modeId = mode.getId();

			// Find the commentStr for this line, if none is found then bail out: we cannot do line comments
			if (seenModes[modeId]) {
				commentStr = seenModes[modeId];
			} else {
				config = LanguageConfigurationRegistry.getComments(mode);
				commentStr = (config ? config.lineCommentToken : null);
				if (!commentStr) {
					// Mode does not support line comments
					return null;
				}

				seenModes[modeId] = commentStr;
			}

			lines.push({
				ignore: false,
				commentStr: commentStr,
				commentStrOffset: 0,
				commentStrLength: commentStr.length
			});
		}

		return lines;
	}

	constructor() {
		super();
		LanguageConfigurationRegistry.register(this.getId(), {
			brackets: [
				['(', ')'],
				['{', '}'],
				['[', ']']
			],

			onEnterRules: [
				{
					// e.g. /** | */
					beforeText: /^\s*\/\*\*(?!\/)([^\*]|\*(?!\/))*$/,
					afterText: /^\s*\*\/$/,
					action: { indentAction: IndentAction.IndentOutdent, appendText: ' * ' }
				},
				{
					// e.g. /** ...|
					beforeText: /^\s*\/\*\*(?!\/)([^\*]|\*(?!\/))*$/,
					action: { indentAction: IndentAction.None, appendText: ' * ' }
				},
				{
					// e.g.  * ...|
					beforeText: /^(\t|(\ \ ))*\ \*(\ ([^\*]|\*(?!\/))*)?$/,
					action: { indentAction: IndentAction.None, appendText: '* ' }
				},
				{
					// e.g.  */|
					beforeText: /^(\t|(\ \ ))*\ \*\/\s*$/,
					action: { indentAction: IndentAction.None, removeText: 1 }
				},
				{
					// e.g.  *-----*/|
					beforeText: /^(\t|(\ \ ))*\ \*[^/]*\*\/\s*$/,
					action: { indentAction: IndentAction.None, removeText: 1 }
				}
			]
		});
	}

		constructor(commentsConfig: CommentRule) {
			super(OUTER_LANGUAGE_ID);
			this._register(LanguageConfigurationRegistry.register(this.getLanguageIdentifier(), {
				comments: commentsConfig
			}));

			this._register(modes.TokenizationRegistry.register(this.getLanguageIdentifier().language, {
				getInitialState: (): modes.IState => NULL_STATE,
				tokenize: undefined,
				tokenize2: (line: string, state: modes.IState): TokenizationResult2 => {
					let languageId = (/^  /.test(line) ? INNER_LANGUAGE_ID : OUTER_LANGUAGE_ID);

					let tokens = new Uint32Array(1 << 1);
					tokens[(0 << 1)] = 0;
					tokens[(0 << 1) + 1] = (
						(modes.ColorId.DefaultForeground << modes.MetadataConsts.FOREGROUND_OFFSET)
						| (languageId.id << modes.MetadataConsts.LANGUAGEID_OFFSET)
					);
					return new TokenizationResult2(tokens, state);
				}
			}));
		}

	test('issue #61296: VS code freezes when editing CSS file with emoji', async function () {
		let toDispose = LanguageConfigurationRegistry.register(modeService.getLanguageIdentifier('fooLang')!, {
			wordPattern: /(#?-?\d*\.\d\w*%?)|(::?[\w-]*(?=[^,{;]*[,{]))|(([@#.!])?[\w-?]+%?|[@#!.])/g
		});
		snippetService = new SimpleSnippetService([new Snippet(
			['fooLang'],
			'bug',
			'-a-bug',
			'',
			'second',
			'',
			SnippetSource.User
		)]);

		const provider = new SnippetCompletionProvider(modeService, snippetService);

		let model = TextModel.createFromString('.🐷-a-b', undefined, modeService.getLanguageIdentifier('fooLang'));
		let result = await provider.provideCompletionItems(model, new Position(1, 8))!;

		assert.equal(result.suggestions.length, 1);

		toDispose.dispose();
	});

	private static _goodIndentForLine(config: CursorConfiguration, model: ITokenizedModel, lineNumber: number): string {
		let lastLineNumber = lineNumber - 1;

		for (lastLineNumber = lineNumber - 1; lastLineNumber >= 1; lastLineNumber--) {
			let lineText = model.getLineContent(lastLineNumber);
			let nonWhitespaceIdx = strings.lastNonWhitespaceIndex(lineText);
			if (nonWhitespaceIdx >= 0) {
				break;
			}
		}

		if (lastLineNumber < 1) {
			// No previous line with content found
			return '\t';
		}

		let r = LanguageConfigurationRegistry.getEnterActionAtPosition(model, lastLineNumber, model.getLineMaxColumn(lastLineNumber));

		let indentation: string;
		if (r.enterAction.indentAction === IndentAction.Outdent) {
			let desiredIndentCount = ShiftCommand.unshiftIndentCount(r.indentation, r.indentation.length, config.tabSize);
			indentation = '';
			for (let i = 0; i < desiredIndentCount; i++) {
				indentation += '\t';
			}
			indentation = config.normalizeIndentation(indentation);
		} else {
			indentation = r.indentation;
		}

		let result = indentation + r.enterAction.appendText;
		if (result.length === 0) {
			// good position is at column 1, but we gotta do something...
			return '\t';
		}
		return result;
	}

	/**
	 * Do an initial pass over the lines and gather info about the line comment string.
	 * Returns null if any of the lines doesn't support a line comment string.
	 */
	public static _gatherPreflightCommentStrings(model: editorCommon.ITokenizedModel, startLineNumber: number, endLineNumber: number): ILinePreflightData[] {

		model.forceTokenization(startLineNumber);
		const languageId = model.getLanguageIdAtPosition(startLineNumber, 1);

		const config = LanguageConfigurationRegistry.getComments(languageId);
		const commentStr = (config ? config.lineCommentToken : null);
		if (!commentStr) {
			// Mode does not support line comments
			return null;
		}

		let lines: ILinePreflightData[] = [];
		for (let i = 0, lineCount = endLineNumber - startLineNumber + 1; i < lineCount; i++) {
			lines[i] = {
				ignore: false,
				commentStr: commentStr,
				commentStrOffset: 0,
				commentStrLength: commentStr.length
			};
		}

		return lines;
	}

	public getEditOperations(model: ITokenizedModel, builder: IEditOperationBuilder): void {
		const startLine = this._selection.startLineNumber;

		let endLine = this._selection.endLineNumber;
		if (this._selection.endColumn === 1 && startLine !== endLine) {
			endLine = endLine - 1;
		}

		const tabSize = this._opts.tabSize;
		const oneIndent = this._opts.oneIndent;
		const shouldIndentEmptyLines = (startLine === endLine);

		// if indenting or outdenting on a whitespace only line
		if (this._selection.isEmpty()) {
			if (/^\s*$/.test(model.getLineContent(startLine))) {
				this._useLastEditRangeForCursorEndPosition = true;
			}
		}

		if (this._opts.useTabStops) {
			// indents[i] represents i * oneIndent
			let indents: string[] = ['', oneIndent];

			// keep track of previous line's "miss-alignment"
			let previousLineExtraSpaces = 0, extraSpaces = 0;
			for (let lineNumber = startLine; lineNumber <= endLine; lineNumber++ , previousLineExtraSpaces = extraSpaces) {
				extraSpaces = 0;
				let lineText = model.getLineContent(lineNumber);
				let indentationEndIndex = strings.firstNonWhitespaceIndex(lineText);

				if (this._opts.isUnshift && (lineText.length === 0 || indentationEndIndex === 0)) {
					// empty line or line with no leading whitespace => nothing to do
					continue;
				}

				if (!shouldIndentEmptyLines && !this._opts.isUnshift && lineText.length === 0) {
					// do not indent empty lines => nothing to do
					continue;
				}

				if (indentationEndIndex === -1) {
					// the entire line is whitespace
					indentationEndIndex = lineText.length;
				}

				if (lineNumber > 1) {
					let contentStartVisibleColumn = CursorColumns.visibleColumnFromColumn(lineText, indentationEndIndex + 1, tabSize);
					if (contentStartVisibleColumn % tabSize !== 0) {
						// The current line is "miss-aligned", so let's see if this is expected...
						// This can only happen when it has trailing commas in the indent
						if (model.isCheapToTokenize(lineNumber - 1)) {
							let enterAction = LanguageConfigurationRegistry.getRawEnterActionAtPosition(model, lineNumber - 1, model.getLineMaxColumn(lineNumber - 1));
							if (enterAction) {
								extraSpaces = previousLineExtraSpaces;
								if (enterAction.appendText) {
									for (let j = 0, lenJ = enterAction.appendText.length; j < lenJ && extraSpaces < tabSize; j++) {
										if (enterAction.appendText.charCodeAt(j) === CharCode.Space) {
											extraSpaces++;
										} else {
											break;
										}
									}
								}
								if (enterAction.removeText) {
									extraSpaces = Math.max(0, extraSpaces - enterAction.removeText);
								}

								// Act as if `prefixSpaces` is not part of the indentation
								for (let j = 0; j < extraSpaces; j++) {
									if (indentationEndIndex === 0 || lineText.charCodeAt(indentationEndIndex - 1) !== CharCode.Space) {
										break;
									}
									indentationEndIndex--;
								}
							}
						}
					}
				}


				if (this._opts.isUnshift && indentationEndIndex === 0) {
					// line with no leading whitespace => nothing to do
					continue;
				}

				let desiredIndentCount: number;
				if (this._opts.isUnshift) {
					desiredIndentCount = ShiftCommand.unshiftIndentCount(lineText, indentationEndIndex + 1, tabSize);
				} else {
					desiredIndentCount = ShiftCommand.shiftIndentCount(lineText, indentationEndIndex + 1, tabSize);
				}

				// Fill `indents`, as needed
				for (let j = indents.length; j <= desiredIndentCount; j++) {
					indents[j] = indents[j - 1] + oneIndent;
				}

				this._addEditOperation(builder, new Range(lineNumber, 1, lineNumber, indentationEndIndex + 1), indents[desiredIndentCount]);
				if (lineNumber === startLine) {
					// Force the startColumn to stay put because we're inserting after it
//.........这里部分代码省略.........

	private static _enter(config: CursorConfiguration, model: ITokenizedModel, keepPosition: boolean, range: Range): EditOperationResult {
		let r = LanguageConfigurationRegistry.getEnterAction(model, range);
		let enterAction = r.enterAction;
		let indentation = r.indentation;

		let beforeText = '';

		if (!r.ignoreCurrentLine) {
			// textBeforeEnter doesn't match unIndentPattern.
			let goodIndent = this._goodIndentForLine(config, model, range.startLineNumber);

			if (goodIndent !== null && goodIndent === r.indentation) {
				if (enterAction.outdentCurrentLine) {
					goodIndent = TypeOperations.unshiftIndent(config, goodIndent);
				}

				let lineText = model.getLineContent(range.startLineNumber);
				if (config.normalizeIndentation(goodIndent) !== config.normalizeIndentation(indentation)) {
					beforeText = config.normalizeIndentation(goodIndent) + lineText.substring(indentation.length, range.startColumn - 1);
					indentation = goodIndent;
					range = new Range(range.startLineNumber, 1, range.endLineNumber, range.endColumn);
				}
			}
		}

		if (enterAction.removeText) {
			indentation = indentation.substring(0, indentation.length - enterAction.removeText);
		}

		let executeCommand: ICommand;
		if (enterAction.indentAction === IndentAction.None) {
			// Nothing special
			executeCommand = TypeOperations.typeCommand(range, beforeText + '\n' + config.normalizeIndentation(indentation + enterAction.appendText), keepPosition);

		} else if (enterAction.indentAction === IndentAction.Indent) {
			// Indent once
			executeCommand = TypeOperations.typeCommand(range, beforeText + '\n' + config.normalizeIndentation(indentation + enterAction.appendText), keepPosition);

		} else if (enterAction.indentAction === IndentAction.IndentOutdent) {
			// Ultra special
			let normalIndent = config.normalizeIndentation(indentation);
			let increasedIndent = config.normalizeIndentation(indentation + enterAction.appendText);

			let typeText = beforeText + '\n' + increasedIndent + '\n' + normalIndent;

			if (keepPosition) {
				executeCommand = new ReplaceCommandWithoutChangingPosition(range, typeText);
			} else {
				executeCommand = new ReplaceCommandWithOffsetCursorState(range, typeText, -1, increasedIndent.length - normalIndent.length);
			}
		} else if (enterAction.indentAction === IndentAction.Outdent) {
			let actualIndentation = TypeOperations.unshiftIndent(config, indentation);
			executeCommand = TypeOperations.typeCommand(range, beforeText + '\n' + config.normalizeIndentation(actualIndentation + enterAction.appendText), keepPosition);
		}

		return new EditOperationResult(executeCommand, {
			shouldPushStackElementBefore: true,
			shouldPushStackElementAfter: false,
			isAutoWhitespaceCommand: true
		});
	}

	constructor(commentsConfig: CommentRule) {
		super();
		LanguageConfigurationRegistry.register(this.getId(), {
			comments: commentsConfig
		});
	}